The present invention relates to a system for the tracking, the securing, and the identification of objects such as keys.
The tracking of keys that open doors of apartments or cars, remains a challenge.
In one known solution, a large number of keys are secured in a locked cabinet, and a computer system interfaces with the cabinet to keep records as to what is kept in the cabinet, who accesses the cabinet, which keys have been withdrawn, and which keys have been returned.
In another known system, a “presence function,” as referred to herein, enables a user to determine whether a key is present or absent, and a related database function can then determine removal and insertion activity by changes in the “presence” data. In addition, a “location” function may be provided, wherein a user can determine where a particular key is located within a cabinet, for example, to facilitate the identification of the location of a specific key.
Common users of these known key management systems include automotive dealerships, which hold keys to many cars on their lots, or multi-dwelling residential buildings, in which the front desk staff have emergency keys for accessing each of the apartments. These systems typically involve (1) an outer cabinet that is locked and unlocked based on a user authentication code or process, (2) multiple preconfigured wired slots, clips or recessed wells, either in the base of a pull-out drawer or on a wall-mounted panel, (3) an assembly whereby each key to be tracked is attached to a special tag containing an “iButton” (as known in the art) or other computer-readable device that has a unique serial number, and/or (4) a mechanism whereby insertion or removal of an iButton/Keytag assembly from/to any of the wired slots is noted by the computer. In this system, upon insertion of iButton/Keytag assembly related information is provided to the computer through the connection provided in the slot. That is, the computer is operatively connected to I/O terminals in each slot which connect to corresponding I/O terminals on a tag in order to send and receive information from the tag.
In addition, some systems provide the wired slots arranged in a grid and the insertion surface is marked with letter and number coordinates (e.g. rows a-z, columns 1-15) and a computer keeps track of the row/column coordinates of the slot in which the key is found. In this way, a computer can direct the user to pick a certain key for a certain apartment by going to location “B7” for example.
In other known systems, the slots are not located in a row/column labeled grid, and the user is instead notified of the location of the key by an LED light that is illuminated at a location of a slot containing the key. In one known system, both methods are used, and the location of a key is identified by a computer providing a row/column coordinate as well as a lighted LED. Providing a way to identify an otherwise unmarked key's location is desirable because the key-tag assembly does not have to be marked with identifying information. Marking keys with identifying information reduces security, such as when keys are removed from a cabinet and circulating. Further, providing a row/column coordinate and/or illuminating a key precludes a need to mark slots in a cabinet with specific information, such as apartment numbers. This prevents a need for staff to return keys to correct slots, thereby removing an extra burden on staff and avoiding confusion when tags are returned to the wrong slot. Furthermore, in the event of a malfunction (e.g. a short) the whole panel must be replaced, which is expensive, and, with a single panel it is difficult to vary the spacing to accommodate objects of different size.
The drawback to using a grid-type arrangement is that the number of slots for receiving tags is fixed. For example, a system can be devised to have 200 slots to accept 200 tags. However, the number of slots cannot be expanded without devising a new panel. Thus, should there be a need to have 230 slots, a new panel having 230 slots must be provided with a new grid numbering. Alternatively, two 200 slot panels must be used to accommodate the extra 30 slots. In short, the use of a single panel containing a plurality of slots with column and row numbering is inflexible.
In another known system, a wireless design is provided, in which a key-tag assembly does not require physical contact with and insertion into a clip within a slot that reads the tag. This design typically utilizes radio frequency identification (“RFID”) tags and antennas instead of iButtons and clips in slots. Each slot for a key may contain a separate antenna (attached to a common RFID reader) and each keytag assembly that is inserted into the “slot” contains a passive RFID tag. Further in this known system, the connection between the keytag assembly RFID tag and the tag “reader” is wireless. The RFID reader activates the different antennas sequentially and reads the RFID tag in each chamber. Similar to the iButton System, the currently known RFID system also requires the specific wiring of each slot.
Yet another known system separates the “presence” and “location” functions, but also uses RFID tags. In this design, the “presence” of a tag in the drawer is detected by a single RFID reader that reads tags throughout a drawer when the drawer is closed. The drawer also has a slot into which each keytag assembly (containing an RFID tag) is inserted and the slot provides simply an on/off indication of a key present or absent (there is “no reader” in the slot that can identify which key is in that slot). In this system, “presence” of all keys is determined when the drawer is closed and when it is re-closed after it had been opened.
It is, however, problematic to get accurate RFID readings of keys present/keys removed in an open field with a drawer open without getting false positives or false negatives of keys removed but nearby. Determining whether a key has been removed or has been added, or determining the location of each specific key is accomplished via a series of logical algorithms. The logical algorithms require the database to keep a running inventory of which keys are in which slots, and which keys have been removed, added or moved to which location by combining data as to which keys have changed in their presence status, and which slots have changed in their occupied/unoccupied status, with provisions being made for keys and locations that are “ambiguous”. Thus, for example, when a few keys are removed and a few keys are returned at the same time the algorithm will have a difficult time to determine which key was returned and which key was taken. The use of this complicated algorithm is necessary because the individual slots are not wired to read the unique IDs of the inserted assemblies, and thus can not determine and report on the location of a specific key assembly directly.
In addition, none of the known systems that utilize multiple RFID tags can be read both when a cabinet is open and when closed, and none enable RFID tags to be read using only a single reader and antenna without having to prewire each slot with its own antenna. The reason for this lies in the limitations of precision for RFID tags and readers. It is problematic to have a precise reading field whereby none of the tags that are in the box are “missed”, and whereby none of the tags that may be located immediately outside of the box or within a few inches are picked up by the readers and marked present. Since known systems provide for a very short-range antenna in each slot, wiring up each slot in a box becomes necessary.
Further, passive tags, typically, require a better “coupling” with the field generated by the reader, and are more prone to false negatives (undetected tags which are present). Active tags, which are self-powered, produce stronger signals independent of the reader's generated field, and are more prone to false positives (reading a tag that has been removed) since their signals can typically travel as far as five feet. Regardless, a known problem with any RFID reader/tag system for tracking purposes is that it requires careful placement and alignment of readers, tags and antennas in order to end up as close to the middle of the false positive-false negative continuum, and even then one is not immune to a certain amount of both error types when working within small distances and around metallic objects.